UPDATE (Jan. 10, 2019, 1:58 p.m.): Following her WWHL appearance, Jax responded to Lindsay's denial on Twitter: "Not that I care, it was over 10 years ago and I am happily engaged... but She’s a liar, my two friends who have nothing to gain, were with me the whole night. That’s all I will say on this. So you are lying darlin." (Read the full text exchange here.)

See MoreLindsay Lohan's Connection to The Real Housewives Just Got Even More Fabulous

With that all cleared up, Lindsay then continued to keep it 100 during her game of Plead the Fifth, revealing to Andy Cohen what she thinks is her biggest career mistake. And, believe us, we didn't see her answer coming.

Hankering for more La Lohan in your life? Well, check her out in action, below.

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Lindsay Lohan & Andy Cohen’s “Parent Trap’ Reenactment

During Clubhouse Playhouse, actress Lindsay Lohan and Andy Cohen reenact a scene from “The Parent Trap” playing the twins and Lindsay gets a kick out of Andy’s portrayal and British accent.